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VMware vSphere Integrated Containers provider (#206)

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* Add Virtual Kubelet provider for VIC

Initial virtual kubelet provider for VMware VIC.  This provider currently
handles creating and starting of a pod VM via the VIC portlayer and persona
server.  Image store handling via the VIC persona server.  This provider
currently requires the feature/wolfpack branch of VIC.

* Added pod stop and delete.  Also added node capacity.

Added the ability to stop and delete pod VMs via VIC.  Also retrieve
node capacity information from the VCH.

* Cleanup and readme file

Some file clean up and added a Readme.md markdown file for the VIC
provider.

* Cleaned up errors, added function comments, moved operation code

1. Cleaned up error handling.  Set standard for creating errors.
2. Added method prototype comments for all interface functions.
3. Moved PodCreator, PodStarter, PodStopper, and PodDeleter to a new folder.

* Add mocking code and unit tests for podcache, podcreator, and podstarter

Used the unit test framework used in VIC to handle assertions in the provider's
unit test.  Mocking code generated using OSS project mockery, which is compatible
with the testify assertion framework.

* Vendored packages for the VIC provider

Requires feature/wolfpack branch of VIC and a few specific commit sha of
projects used within VIC.

* Implementation of POD Stopper and Deleter unit tests (#4)

* Updated files for initial PR
This commit is contained in:
Loc Nguyen
2018-06-04 15:41:32 -07:00
committed by Ria Bhatia
parent 98a111e8b7
commit 513cebe7b7
6296 changed files with 1123685 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

58
vendor/github.com/vmware/vic/pkg/fetcher/errors.go generated vendored Normal file
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// Copyright 2016 VMware, Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package fetcher
import (
"fmt"
"net/url"
)
// DoNotRetry is an error wrapper indicating that the error cannot be resolved with a retry.
type DoNotRetry struct {
Err error
}
// Error returns the stringified representation of the encapsulated error.
func (e DoNotRetry) Error() string {
return fmt.Sprintf("download failed: %s", e.Err.Error())
}
// ImageNotFoundError is returned when an image is not found.
type ImageNotFoundError struct {
Err error
}
func (e ImageNotFoundError) Error() string {
return fmt.Sprintf("image not found: %s", e.Err.Error())
}
// TagNotFoundError is returned when an image's tag doesn't exist.
type TagNotFoundError struct {
Err error
}
func (e TagNotFoundError) Error() string {
return fmt.Sprintf("image tag not found: %s", e.Err.Error())
}
// AuthTokenError is returned when authentication with a registry fails
type AuthTokenError struct {
TokenServer url.URL
Err error
}
func (e AuthTokenError) Error() string {
return fmt.Sprintf("Failed to fetch auth token from %s", e.TokenServer.Host)
}

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vendor/github.com/vmware/vic/pkg/fetcher/fetcher.go generated vendored Normal file
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// Copyright 2016-2017 VMware, Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package fetcher
import (
"bytes"
"context"
"crypto/tls"
"crypto/x509"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/url"
"os"
"strconv"
"strings"
"time"
log "github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/ioutils"
"github.com/docker/docker/pkg/progress"
"golang.org/x/net/context/ctxhttp"
"github.com/vmware/vic/pkg/trace"
"github.com/vmware/vic/pkg/version"
)
const (
maxDownloadAttempts = 5
// DefaultTokenExpirationDuration specifies the default token expiration
DefaultTokenExpirationDuration = 60 * time.Second
)
// Fetcher interface
type Fetcher interface {
Fetch(ctx context.Context, url *url.URL, reqHdrs *http.Header, toFile bool, po progress.Output, id ...string) (string, error)
FetchAuthToken(url *url.URL) (*Token, error)
Ping(url *url.URL) (http.Header, error)
Head(url *url.URL) (http.Header, error)
ExtractOAuthURL(hdr string, repository *url.URL) (*url.URL, error)
IsStatusUnauthorized() bool
IsStatusOK() bool
IsStatusNotFound() bool
AuthURL() *url.URL
}
// Token represents https://docs.docker.com/registry/spec/auth/token/
type Token struct {
// An opaque Bearer token that clients should supply to subsequent requests in the Authorization header.
Token string `json:"token"`
// (Optional) The duration in seconds since the token was issued that it will remain valid. When omitted, this defaults to 60 seconds.
Expires time.Time
ExpiresIn int `json:"expires_in"`
IssueAt time.Time `json:"issued_at"`
}
// Options struct
type Options struct {
Timeout time.Duration
Username string
Password string
InsecureSkipVerify bool
Token *Token
// RootCAs will not be modified by fetcher.
RootCAs *x509.CertPool
}
// URLFetcher struct
type URLFetcher struct {
client *http.Client
OAuthEndpoint *url.URL
StatusCode int
options Options
}
// RegistryErrorRespBody is used for unmarshaling json error response body from image registries.
// Error response json is assumed to follow Docker API convention (field `details` is dropped).
// See: https://docs.docker.com/registry/spec/api/#errors
type RegistryErrorRespBody struct {
Errors []struct {
Code string
Message string
}
}
// NewURLFetcher creates a new URLFetcher
func NewURLFetcher(options Options) Fetcher {
/* #nosec */
tr := &http.Transport{
Proxy: http.ProxyFromEnvironment,
TLSClientConfig: &tls.Config{
InsecureSkipVerify: options.InsecureSkipVerify,
RootCAs: options.RootCAs,
},
}
client := &http.Client{Transport: tr}
return &URLFetcher{
client: client,
options: options,
}
}
// Fetch fetches from a url and stores its content in a temporary file.
// hdrs is optional.
func (u *URLFetcher) Fetch(ctx context.Context, url *url.URL, reqHdrs *http.Header, toFile bool, po progress.Output, ids ...string) (string, error) {
defer trace.End(trace.Begin(url.String()))
// extract ID from ids. Existence of an ID enables progress reporting
ID := ""
if len(ids) > 0 {
ID = ids[0]
}
// ctx
ctx, cancel := context.WithTimeout(context.Background(), u.options.Timeout)
defer cancel()
var data string
var err error
var retries int
for {
if toFile {
data, err = u.fetchToFile(ctx, url, reqHdrs, ID, po)
} else {
data, err = u.fetchToString(ctx, url, reqHdrs, ID)
}
if err == nil {
return data, nil
}
// If an error was returned because the context was cancelled, we shouldn't retry.
select {
case <-ctx.Done():
return "", fmt.Errorf("download cancelled during download")
default:
}
retries++
// give up if we reached maxDownloadAttempts
if retries == maxDownloadAttempts {
log.Debugf("Hit max download attempts. Download failed: %v", err)
return "", err
}
switch err := err.(type) {
case DoNotRetry, TagNotFoundError, ImageNotFoundError:
log.Debugf("Error: %s", err.Error())
return "", err
}
// retry downloading again
log.Debugf("Download failed, retrying: %v", err)
delay := retries * 5
ticker := time.NewTicker(time.Second)
selectLoop:
for {
// Do not report progress back if ID is empty
if ID != "" && po != nil {
progress.Updatef(po, ID, "Retrying in %d second%s", delay, (map[bool]string{true: "s"})[delay != 1])
}
select {
case <-ticker.C:
delay--
if delay == 0 {
ticker.Stop()
break selectLoop
}
case <-ctx.Done():
ticker.Stop()
return "", fmt.Errorf("download cancelled during retry delay")
}
}
}
}
func (u *URLFetcher) FetchAuthToken(url *url.URL) (*Token, error) {
defer trace.End(trace.Begin(url.String()))
data, err := u.Fetch(context.Background(), url, nil, false, nil)
if err != nil {
log.Errorf("Download failed: %v", err)
return nil, err
}
token := &Token{}
err = json.Unmarshal([]byte(data), &token)
if err != nil {
log.Errorf("Incorrect token format: %v", err)
return nil, err
}
if token.ExpiresIn == 0 {
token.Expires = time.Now().Add(DefaultTokenExpirationDuration)
} else {
token.Expires = time.Now().Add(time.Duration(token.ExpiresIn) * time.Second)
}
return token, nil
}
func (u *URLFetcher) fetch(ctx context.Context, url *url.URL, reqHdrs *http.Header, ID string) (io.ReadCloser, http.Header, error) {
req, err := http.NewRequest("GET", url.String(), nil)
if err != nil {
return nil, nil, err
}
u.setBasicAuth(req)
u.setAuthToken(req)
u.setUserAgent(req)
// Add optional request headers
if reqHdrs != nil {
for k, values := range *reqHdrs {
for _, v := range values {
req.Header.Add(k, v)
}
}
}
res, err := ctxhttp.Do(ctx, u.client, req)
if err != nil {
return nil, nil, err
}
u.StatusCode = res.StatusCode
if u.IsNonretryableClientError() {
if u.options.Token == nil && u.IsStatusUnauthorized() {
hdr := res.Header.Get("www-authenticate")
if hdr == "" {
return nil, nil, DoNotRetry{fmt.Errorf("www-authenticate header is missing")}
}
u.OAuthEndpoint, err = u.ExtractOAuthURL(hdr, url)
if err != nil {
return nil, nil, err
}
return nil, nil, DoNotRetry{Err: fmt.Errorf("Authentication required")}
}
if u.IsStatusNotFound() {
err = fmt.Errorf("Not found: %d, URL: %s", u.StatusCode, url)
return nil, nil, TagNotFoundError{Err: err}
}
if u.IsStatusUnauthorized() {
hdr := res.Header.Get("www-authenticate")
// check if image is non-existent (#757)
if strings.Contains(hdr, "error=\"insufficient_scope\"") {
err = fmt.Errorf("image not found")
return nil, nil, ImageNotFoundError{Err: err}
} else if strings.Contains(hdr, "error=\"invalid_token\"") {
return nil, nil, fmt.Errorf("not authorized")
} else {
return nil, nil, fmt.Errorf("Unexpected http code: %d, URL: %s", u.StatusCode, url)
}
}
// for all other non-retryable client errors, grab the error message if there is one (#5951)
err := fmt.Errorf(u.buildRegistryErrMsg(url, res.Body))
return nil, nil, DoNotRetry{Err: err}
}
// FIXME: handle StatusTemporaryRedirect and StatusFound
// for all other unexpected http codes, grab the message out if there is one (#5951)
if !u.IsStatusOK() {
err := fmt.Errorf(u.buildRegistryErrMsg(url, res.Body))
return nil, nil, err
}
log.Debugf("URLFetcher.fetch() - %#v, %#v", res.Body, res.Header)
return res.Body, res.Header, nil
}
// fetch fetches the given URL using ctxhttp. It also streams back the progress bar only when ID is not an empty string.
func (u *URLFetcher) fetchToFile(ctx context.Context, url *url.URL, reqHdrs *http.Header, ID string, po progress.Output) (string, error) {
rdr, hdrs, err := u.fetch(ctx, url, reqHdrs, ID)
if err != nil {
return "", err
}
defer rdr.Close()
// stream progress as json and body into a file - only if we have an ID and a Content-Length header
if contLen := hdrs.Get("Content-Length"); ID != "" && contLen != "" {
cl, cerr := strconv.ParseInt(contLen, 10, 64)
if cerr != nil {
return "", cerr
}
if po != nil {
rdr = progress.NewProgressReader(
ioutils.NewCancelReadCloser(ctx, rdr), po, cl, ID, "Downloading",
)
defer rdr.Close()
} else {
rdr = ioutils.NewCancelReadCloser(ctx, rdr)
}
}
// Create a temporary file and stream the res.Body into it
out, err := ioutil.TempFile(os.TempDir(), ID)
if err != nil {
return "", DoNotRetry{Err: err}
}
defer out.Close()
// Stream into it
_, err = io.Copy(out, rdr)
if err != nil {
log.Errorf("Fetch (%s) to file failed to stream to file: %s", url.String(), err)
// cleanup
defer os.Remove(out.Name())
return "", DoNotRetry{Err: err}
}
// Return the temporary file name
return out.Name(), nil
}
// fetch fetches the given URL using ctxhttp. It also streams back the progress bar only when ID is not an empty string.
func (u *URLFetcher) fetchToString(ctx context.Context, url *url.URL, reqHdrs *http.Header, ID string) (string, error) {
rdr, _, err := u.fetch(ctx, url, reqHdrs, ID)
if err != nil {
log.Errorf("Fetch (%s) to string error: %s", url.String(), err)
return "", err
}
defer rdr.Close()
out := bytes.NewBuffer(nil)
// Stream into it
_, err = io.Copy(out, rdr)
if err != nil {
// cleanup
return "", DoNotRetry{Err: err}
}
// Return the string
return string(out.Bytes()), nil
}
// Ping sends a GET request to an url and returns the header if successful
func (u *URLFetcher) Ping(url *url.URL) (http.Header, error) {
ctx, cancel := context.WithTimeout(context.Background(), u.options.Timeout)
defer cancel()
res, err := ctxhttp.Get(ctx, u.client, url.String())
if err != nil {
return nil, err
}
defer res.Body.Close()
u.StatusCode = res.StatusCode
if u.IsStatusUnauthorized() || u.IsStatusOK() {
log.Debugf("header = %#v", res.Header)
return res.Header, nil
}
return nil, fmt.Errorf("Unexpected http code: %d, URL: %s", u.StatusCode, url)
}
// Head sends a HEAD request to url
func (u *URLFetcher) Head(url *url.URL) (http.Header, error) {
ctx, cancel := context.WithTimeout(context.Background(), u.options.Timeout)
defer cancel()
res, err := ctxhttp.Head(ctx, u.client, url.String())
if err != nil {
return nil, err
}
defer res.Body.Close()
u.StatusCode = res.StatusCode
if u.IsStatusUnauthorized() || u.IsStatusOK() {
return res.Header, nil
}
return nil, fmt.Errorf("Unexpected http code: %d, URL: %s", u.StatusCode, url)
}
// AuthURL returns the Oauth endpoint URL
func (u *URLFetcher) AuthURL() *url.URL {
return u.OAuthEndpoint
}
// IsStatusUnauthorized returns true if status code is StatusUnauthorized
func (u *URLFetcher) IsStatusUnauthorized() bool {
return u.StatusCode == http.StatusUnauthorized
}
// IsStatusOK returns true if status code is StatusOK
func (u *URLFetcher) IsStatusOK() bool {
return u.StatusCode == http.StatusOK
}
// IsStatusNotFound returns true if status code is StatusNotFound
func (u *URLFetcher) IsStatusNotFound() bool {
return u.StatusCode == http.StatusNotFound
}
// IsNonretryableClientError returns true if status code is a nonretryable 4XX error. This includes
// all 4XX errors except 'locked', and 'too many requests'.
func (u *URLFetcher) IsNonretryableClientError() bool {
s := u.StatusCode
return 400 <= s && s < 500 &&
s != http.StatusLocked && s != http.StatusTooManyRequests
}
// buildRegistryErrMsg builds error message for unexpected http code (nonretryable client errors and all other errors)
// and extracts message details from response body stream if there is one (#5951).
func (u *URLFetcher) buildRegistryErrMsg(url *url.URL, respBody io.ReadCloser) string {
errMsg := fmt.Sprintf("Unexpected http code: %d (%s), URL: %s", u.StatusCode, http.StatusText(u.StatusCode), url)
errDetail, err := extractErrResponseMessage(respBody)
if err != nil {
return errMsg
}
if strings.Contains(errDetail, "does not have permission") {
errMsg = fmt.Sprintf("unauthorized: %s", errDetail)
} else {
errMsg += fmt.Sprintf("Message: %s", errDetail)
}
return errMsg
}
// malformedJsonErrFormat is the error format for malformed json response body
// used in function extractErrResponseMessage
var errJSONFormat = fmt.Errorf("error response json has unconventional format")
// extractErrResponseMessage extracts `message` field from error response body stream.
func extractErrResponseMessage(rdr io.ReadCloser) (string, error) {
// close the stream after done
defer rdr.Close()
out := bytes.NewBuffer(nil)
_, err := io.Copy(out, rdr)
if err != nil {
log.Debugf("Error when copying from error response body stream: %s", err)
return "", err
}
res := []byte(out.Bytes())
log.Debugf("Error message json string: %s", string(res))
var errResponse RegistryErrorRespBody
err = json.Unmarshal(res, &errResponse)
if err != nil {
log.Debugf("Error when unmarshaling error response body: %s", err)
return "", err
}
if len(errResponse.Errors) == 0 {
log.Debugf("Error response wrong format. Response body: %s", string(res))
return "", errJSONFormat
}
// grab out every error message
var errString string
for i := range errResponse.Errors {
message := errResponse.Errors[i].Message
// only append the message when there is content in the field
if len(message) > 0 {
if i > 0 {
errString += ", "
}
errString += message
}
}
// if no message available, treat it as a malformed json error
if len(errString) == 0 {
return "", errJSONFormat
}
return errString, nil
}
func (u *URLFetcher) setUserAgent(req *http.Request) {
log.Debugf("Setting user-agent to vic/%s", version.Version)
req.Header.Set("User-Agent", "vic/"+version.Version)
}
func (u *URLFetcher) setBasicAuth(req *http.Request) {
if u.options.Username != "" && u.options.Password != "" {
log.Debugf("Setting BasicAuth: %s", u.options.Username)
req.SetBasicAuth(u.options.Username, u.options.Password)
}
}
func (u *URLFetcher) setAuthToken(req *http.Request) {
if u.options.Token != nil {
req.Header.Set("Authorization", "Bearer "+u.options.Token.Token)
}
}
// ExtractOAuthURL extracts the OAuth url from the www-authenticate header
func (u *URLFetcher) ExtractOAuthURL(hdr string, repository *url.URL) (*url.URL, error) {
tokens := strings.Split(hdr, " ")
if len(tokens) != 2 || strings.ToLower(tokens[0]) != "bearer" {
err := fmt.Errorf("www-authenticate header is corrupted")
return nil, DoNotRetry{Err: err}
}
tokens = strings.Split(tokens[1], ",")
var realm, service, scope string
for _, token := range tokens {
if strings.HasPrefix(token, "realm") {
realm = strings.Trim(token[len("realm="):], "\"")
}
if strings.HasPrefix(token, "service") {
service = strings.Trim(token[len("service="):], "\"")
}
if strings.HasPrefix(token, "scope") {
scope = strings.Trim(token[len("scope="):], "\"")
}
}
if realm == "" {
err := fmt.Errorf("missing realm in bearer auth challenge")
return nil, DoNotRetry{Err: err}
}
if service == "" {
err := fmt.Errorf("missing service in bearer auth challenge")
return nil, DoNotRetry{Err: err}
}
// The scope can be empty if we're not getting a token for a specific repo
if scope == "" && repository != nil {
err := fmt.Errorf("missing scope in bearer auth challenge")
return nil, DoNotRetry{Err: err}
}
auth, err := url.Parse(realm)
if err != nil {
return nil, err
}
q := auth.Query()
q.Add("service", service)
if scope != "" {
q.Add("scope", scope)
}
auth.RawQuery = q.Encode()
return auth, nil
}

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vendor/github.com/vmware/vic/pkg/fetcher/fetcher_test.go generated vendored Normal file
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// Copyright 2017 VMware, Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package fetcher
import (
"bytes"
"io/ioutil"
"testing"
"github.com/stretchr/testify/assert"
)
const (
errJSONStr401 = `{
"errors":
[{"code":"UNAUTHORIZED",
"message":"authentication required",
"detail":[{"Type":"repository","Class":"","Name":"library/jiowengew","Action":"pull"}]
}]
}
`
multipleErrJSONStr = `{
"errors":
[{"code":"UNAUTHORIZED",
"message":"authentication required",
"detail":[{"Type":"repository","Class":"","Name":"library/jiowengew","Action":"pull"}]
},
{"code":"NOTFOUND",
"message": "image not found",
"detail": "image not found"
}]
}
`
unexpectedStr = `random`
unexpectedJSONStr = `{"nope":"nope"}`
errJSONWithEmptyErrorsField = `{"errors":[]}`
errJSONWithNoMessageField = `{"errors":[{"code":"nope","detail":"nope"}]}`
errJSONWithEmptyMessageField = `{"errors":[{"code":"nope","message":""},{"message":""}]}`
)
func TestExtractErrResponseMessage(t *testing.T) {
// Test set up: create the io streams for testing purposes
// multiple streams needed: these streams only have read ends
singleErrTestStream := ioutil.NopCloser(bytes.NewReader([]byte(errJSONStr401)))
multipleErrTestStream := ioutil.NopCloser(bytes.NewReader([]byte(multipleErrJSONStr)))
unexpectedStrTestStream := ioutil.NopCloser(bytes.NewReader([]byte(unexpectedStr)))
malformedJSONTestStream := ioutil.NopCloser(bytes.NewReader([]byte(unexpectedJSONStr)))
emptyErrorsJSONTestStream := ioutil.NopCloser(bytes.NewReader([]byte(errJSONWithEmptyErrorsField)))
noMessageJSONTestStream := ioutil.NopCloser(bytes.NewReader([]byte(errJSONWithNoMessageField)))
emptyMessageJSONTestStream := ioutil.NopCloser(bytes.NewReader([]byte(errJSONWithEmptyMessageField)))
// Test 1: single error message extraction
msg, err := extractErrResponseMessage(singleErrTestStream)
assert.Nil(t, err, "test: (single error message) extraction should success for well-formatted error json")
assert.Equal(t, "authentication required", msg,
"test: (single error message) extracted message: %s; expected: authentication required", msg)
// Test 2: multiple error message extraction
msg, err = extractErrResponseMessage(multipleErrTestStream)
assert.Nil(t, err, "test: (multiple error messages) extraction should success for well-formatted error json")
assert.Equal(t, "authentication required, image not found", msg,
"test: (multiple error messages) extracted message: %s; expected: authentication required, image not found", msg)
// Test 3: random string in the stream that is not a json
msg, err = extractErrResponseMessage(unexpectedStrTestStream)
assert.Equal(t, "", msg, "test: (non-json string) no message should be extracted")
assert.NotNil(t, err, "test: (non-json string) extraction should fail")
// Test 4: malformed json string
msg, err = extractErrResponseMessage(malformedJSONTestStream)
assert.Equal(t, "", msg, "test: (malformed json string) no message should be extracted")
assert.Equal(t, errJSONFormat, err,
"test: (malformed json string) error: %s; expected error: %s", err)
// Test 5: malformed json with empty `errors` field
msg, err = extractErrResponseMessage(emptyErrorsJSONTestStream)
assert.Equal(t, "", msg, "test: (malformed json string, empty errors field) no message should be extracted")
assert.Equal(t, errJSONFormat, err,
"test: (malformerrJsonFormated json string, empty errors field) error: %s; expected error: %s", err, errJSONFormat)
// Test 6: malformed json with no `message` field
msg, err = extractErrResponseMessage(noMessageJSONTestStream)
assert.Equal(t, "", msg, "test: (malformed json string, no message field) no message should be extracted")
assert.Equal(t, errJSONFormat, err,
"test: (malformed json string, no message field) error: %s; expected error: %s", err, errJSONFormat)
// Test 7: malformed json with empty string in `message` field
msg, err = extractErrResponseMessage(emptyMessageJSONTestStream)
assert.Equal(t, "", msg, "test: (malformed json string, empty message field) no message should be extracted")
assert.Equal(t, errJSONFormat, err,
"test: (malformed json string, empty message field) error: %s; expected error: %s", err, errJSONFormat)
}